1. Field of the Invention
This invention relates to canister type vacuum cleaners and in particular to a vacuum apparatus which has a protective device for protecting an operator using same against any injury likely to cause harm.
2. Prior Art Statement
Canister type vacuum cleaners are well known and each employs a vacuum tank having an electrically powered vacuum unit, an electric motor driven cleaning instrument for operation remote from the vacuum tank, and a vacuum hose assembly operatively connecting the cleaning instrument to the tank. The vacuum hose assembly used in this type of vacuum system usually has dual-purpose electrical conductors and reinforcing wires extending therealong for purposes well known in the art. However, in the normal operation of a vacuum cleaner, numerous electrical failures can occur in one or more components of such vacuum cleaner. Further, the vacuum cleaner may be intentionally or inadvertantly operated on damp or wet floors. In the event of failure of an electrical component or operation of the vacuum cleaner on a damp or wet floor the risk of serious injury to an operator is great.
It is known to provide electrical protective devices on electrical equipment including on vacuum cleaners; however, the main thrust of most previous devices has been to protect the electrical equipment.
Electrical devices sensitive to practically every type of fault capable of causing injury to humans and serving to detect such fault while operating to interrupt a circuit therethrough upon detection of the fault have been proposed heretofore and such a device is disclosed in U.S. Pat. No. 3,493,815. It has also been proposed in U.S. Pat. No. 4,168,564 to provide a thermally actuated switch in the electrical circuit of a vacuum hose assembly wherein such switch breaks the electrical circuit through cooperating electrical leads of electrical system thereof once a predetermined temperature level is reached by the switch. In addition, it is known to provide a conventional fuse in a vacuum cleaning apparatus. Finally, it has also been proposed to provide a so-called portable ground fault circuit interrupter which consists of a portable box having a plug at one end for plugging into a grounded power supply and one or more female plugs therein for plugging tools therein.